Two bugs reported on the docker terminal backend (desktop app, sandboxed
profiles with container_persistent: false):
1. A NEW chat's container inherited the PREVIOUS session's workspace,
bind-mounted rw at /workspace, because the mount source was the
process-global TERMINAL_CWD env var (written by the workspace picker,
outliving its session) and all sessions shared one 'default' container.
2. Every command failed with exit 126 because the desktop gateway recorded
the HOST launch directory as the session cwd, and each command was
prefixed with 'cd /Users/<user>/...' inside the container.
Fixes (class-wide, single owners):
- container_persistent: false + docker now keys containers PER SESSION:
fresh container per chat, removed at session close/idle. delegate_task
children share the parent's container via an explicit alias registry.
container_persistent: true keeps the documented ONE-long-lived-container
contract unchanged.
- _resolve_task_host_cwd() is the single owner of the cwd->/workspace mount
policy across all four env-creation sites; under isolation it refuses
process-global cwd sources and mounts only the session's own attached
workspace (tui_gateway now tags overrides with cwd_source).
- _resolve_command_cwd() gains the same host-path guard the env-creation
sites already had (#50636/#54447 sibling site): a recorded host cwd is
discarded on container backends instead of cd-ing every command into a
nonexistent path.
E2E-tested against real Docker: distinct containers per session, no stale
mount in a fresh session, no exit 126 from host cwd records, containers
removed at session teardown.